GB/T 14949.9-1994 Chemical analysis methods for manganese ores - Determination of sulfur content
Some standard content:
National Standard of the People's Republic of China
Chemical analysis method of manganese ore
Determination of sulfur content
Manganese ores-Determinatian af sulphur contentsThis standard is equivalent to the international standard IS0320-1981 "Manganese ore titration method".
Part I
1 Subject content and scope of application
This standard specifies the determination of sulfur content by barium sulfate gravimetric method. Determination of sulfur content
Barium sulfate gravimetric method
This standard is applicable to the determination of sulfur groups in manganese ore and manganese concentrate. Determination range: 0.2% to 10%.
2 Method Summary
GB/T 14949.9--94
Replaces GB151:79
Barium Sulfate Coulometric Method and Combustion Iodine Content
Melting the ore sample with sodium peroxide and sodium carbonate at 650~700C. The sulfur contained in the ore sample (usually in the form of pyrite and barite) is converted into sodium sulfate. The molten material is extracted with water and then filtered to separate the sulfate from other interfering elements. The sulfate in the filtrate is precipitated with barium chloride and the sulfur content is determined in the form of barium sulfate. 3 Reagents
3.1 Mixed flux: Mix 20g of anhydrous sodium carbonate and 30g of sodium peroxide, crush and mix well. 3.2 Ethanol.
3.3 Sodium carbonate solution (10g/L).
3.4 Hydrochloric acid (3+2).
3.5 Barium chloride solution (100 g/L).
3.6 Washing solution
Add 10 ml of barium chloride solution (3.5) to 10 mL of hydrochloric acid (1+1), and dilute with water to 11. 3.7 Silver nitrate solution (1 g/L).
3.8 Methyl red indicator (1 g/L) ethanol medium. 4 Apparatus
Usual laboratory equipment and
4.1 Nickel crucible.
Approved by the State Administration of Technical Supervision in 1994-0118
Implementation in 1994.10-01
4.2 Porcelain Kun glass.
4.3 Muffle furnace,
5 Sample
GB/T 14949.9--
The sample should pass through a 0.100 mm sieve and be ventilated under laboratory conditions. 6 Analysis steps
6.1 Sample quantity
Weigh 1~2g of sample, accurate to 0.0001g. When the sulfur content in the sample is less than 1%, weigh 2g; when the sulfur content is equal to 1%, weigh 1g
Weigh the sample at the same time as the determination, and determine the mass percentage of wet water (A). When calculating the sulfur content, the result (mass fraction) should be multiplied by the conversion factor (K), which is the mass percentage of sulfur content determined in the completely dry sample. 100bzxZ.net
Conversion factor =
6.2 Blank test
Carry out a blank test with the sample.
6.3 Determination
6.3.1 Place the sample (6.1) in nickel (4.1), add 10g of mixed flux (3.1), and mix carefully. Cover it with 1~2g of mixed flux.
6.3.2 Place the crucible in a muffle furnace (4.3) heated to about 550°C, continue heating, and keep it at 650-700°C for 20 minutes. Take it out and let it cool slightly. Place the crucible in a 500mL beaker containing about 150mL of water, heat and boil for 3-5 minutes, take out the crucible and rinse it with hot water. Boil it again for 3-5 minutes.
6.3.3 If the solution has the green color of manganese salt, add a few drops of ethanol (3.2) to reduce manganese. Heat and boil again until the green color of manganese salt fades. 6.3.4 Filter the hot solution through quantitative filter paper into a 500mL beaker, transfer the solution and residue onto the filter paper, and wash the beaker and filter paper once with sodium carbonate solution (3.3). Then use a medicine spoon to carefully remove most of the precipitate on the filter paper, put it into the original beaker, rinse the medicine spoon with sodium carbonate solution (3.3), and take it out. And wash the precipitate on the filter paper once with hot sodium carbonate solution (3.3). Add 50~80ml sodium carbonate solution (3.3) to the original beaker and boil for 510min. Pass the solution through the same filter paper and transfer the precipitate to the filter paper, then wash the precipitate and beaker with hot sodium carbonate solution (3.3) 6~8 times (the filtrate is about 300mL at this time). 6.3.5 Add 2 drops of base red indicator (3.8) to the filtrate, neutralize with hydrochloric acid (3.4) until the solution turns red, and immediately add 2.5ml in excess. 6.3.6 To prevent boiling, press a small piece of quantitative filter paper under the glass rod and cover with Table III. Heat the solution and boil for about 5min to drive out carbon dioxide. Then add hot (60~70℃) barium chloride solution (3.5) dropwise with constant stirring. When the sulfur content is less than or equal to 5%, add 10ml barium chloride solution (3.5); when it is greater than 5%, add 15mL. Place the small piece of filter paper under the glass rod and boil it slightly to reduce its volume to about 250 ml. Then, let the solution containing sulfuric acid precipitate stand for more than 12 hours. Filter on a slow quantitative filter paper containing a small amount of quantitative filter paper pulp, collect the precipitate, and wash the beaker and precipitate 23 times with cold washing liquid (3.6). Then wash with warm water until there is no nitrogen ion (check with silver nitrate solution (3.7)).
6.3.7 Place the filter paper and precipitate in a constant weight porcelain (4.2). After drying and ashing in an electric furnace, place it in a muffle furnace (4.3) and burn it at 800℃ for 20 to 30 minutes. Take it out, cool it slightly, put the porcelain in a desiccator, and weigh it after cooling. And burn it to a constant weight. 7 Calculation of analysis results
The mass percentage of sulfur is calculated as follows: s(%) = (ml= m.) × 0. 137 4× 100 ×k315
Wherein: mt-mass of barium sulfate, g;
GB/T 14949.9--94
m.--mass of barium sulfate in blank test, g; m-mass of sample + g
0.1374-coefficient of conversion of barium sulfate to sulfur; K-mass percentage conversion coefficient of sulfur in completely dry sample. 8 Precision
The precision listed in this standard is obtained by nine laboratories in 1990 on four uniform samples evenly distributed in the determination range of this method, according to the analysis steps of this method, and after jointly conducting the test, the data are summarized and statistically analyzed in accordance with the national standard GB6379. The repeatability r and reproducibility R are shown in Table 1. The original data are shown in Appendix A1 (Supplement). Table 1
Level, % (m/m)
0.30~10.0
Repeatability,
-1. 522+0. 555 1 igm
Reproducibility R
IgR 1.4021 0.854 41gm
Repeatability is the maximum difference between two independent test results at a 95% probability level when two single test results are made by the same operator in the same laboratory using the same instrument and within a short period of time under normal and correct operation conditions. Reproducibility is the maximum difference between two independent test results at a 95% probability level when two single test results are made by two operators in different laboratories under normal and correct operation conditions for the same sample. If the difference between two independent test results exceeds the corresponding repeatability and reproducibility values, the two results are considered suspicious. Part 2 Combustion Iodometric Titration
9 Subject Content and Scope of Application
This standard specifies the determination of sulfur content by combustion iodometric titration. This standard is applicable to the determination of sulfur content in manganese ore. Determination range: 0.010% to 0.30%. 10 Method Summary
The sample is burned in a nitrogen flow at 1200 to 1250°C or in an oxygen flow at 1350 to 1400°C. The generated sulfur oxide is introduced into an absorption liquid containing starch, and the generated sulfurous acid is titrated with a potassium iodate standard solution under the indication of starch. 11 Reagents
11.1 Calcium chloride: anhydrous block.
11.2 Potassium hydroxide: granular.
11.3 Potassium hydroxide solution (300g/L). 11.4 Sulfuric acid (pl.84g/mL).
11.5 Starch solution (10g/L): Weigh 1.0 ml of starch, cover it in a 200ml beaker, add 10ml of water to make a suspension, add 7080ml of boiling water, stir and heat to boiling, remove and add 3~4 drops of hydrochloric acid (pl.19g/ml.), cool to room temperature, dilute with water to 100ml, and mix.
11.6 Starch absorption liquid (0.5g/l): Measure 25ml. starch solution (11.5) and place it in a 500ml volumetric flask, add 15ml. hot acid (ml.19g/ml), dilute with water to the scale, and mix. x1
11.7 Potassium iodide solution (30g/1.)
GB/\14949.9---94
11.8 Potassium iodate standard solution ((1/6k10) - 0.0025nol/l) 11.8.1 Preparation of solution
Weigh 0.1783g of iodic acid into a 100ml beaker. Add 1g of potassium iodide. Dissolve it in water and then add 1g of potassium hydroxide (11.2). After it is completely dissolved, transfer it into a 2000ml volumetric flask, dilute it to the scale with water and mix it well. 11.8.2 Calibration of potassium iodate standard solution
Take three portions of manganese ore standard samples with sulfur content close to that of the sample to be tested and perform the analysis according to step 14. The extreme difference in the number of milliliters of potassium iodate standard solution (11.8) consumed shall not exceed 0.10ml. Take the average value. The titer of potassium iodate standard solution (11.8) is calculated according to formula (1): Bxm
-(V-- V) 100
Wherein: T-titre of potassium iodate standard solution, grams of sulfur equivalent to each milliliter of solution; B-mass percentage of sulfur content in the standard sample; m1---mass of standard sample converted to completely dry; V---volume of potassium iodate standard solution consumed by the standard sample, mLV....--volume of potassium iodate standard solution consumed by the blank test during calibration, mL.12 Instruments and devices
12.1 The device for determining sulfur is shown in Figure 1.
"Nitrogen cylinder (or oxygen cylinder); 2Oxygen pressure gauge 3Potassium hydroxide solution in the washing bottle (11.3); 4 Sulfuric acid (11.4) in the washing bottle: 5 Lower drying tower; (the lower half is filled with potassium hydroxide (11.2), with a glass wool filter layer in the middle, and the upper half is filled with calcium fluoride (11.1). There is a glass wool filter layer above the calcium chloride. When using nitrogen, only calcium chloride (11.1) needs to be filled, and the two washing bottles 4 and 5 are not needed); 6 Combustion furnace (the temperature can reach 1400 (); 7 Temperature controller (controllable 1400); 8 Glass single ball drying tube (with lower drying absorbent cotton); 9 Sulfur absorption cup (for absorbing sulfur dioxide): 10 Burette; 11 ：Porcelain tube (inner diameter 23l.2mm, length 600mm); 12 Porcelain boat (length 88mm.77mm or 96mm); 13 Sulfur absorption cup (for reference) 12.2 Sulfur absorption cup see Figure 2.
13 Sample
GB/T14949.9--94
022~23
Float (frosted)
Spray downward
The sample should pass through a 0.100mm sieve and be air-dried under laboratory conditions. 14 Analysis steps
14.1 Sample quantity
Weigh 0.5~1.0g of the sample, accurate to 0.0001g. When the sulfur content in the sample is less than or equal to 0.02%, weigh about 1g, and when it is greater than 0.02%, weigh about 0.5g.
While measuring, weigh the sample to determine the mass fraction of wet water (A). When calculating the sulfur content, the result (mass white fraction) should be multiplied by the conversion factor K, which is the mass percentage of sulfur measured in the completely dry sample. Conversion factor K
14.2 Blank test
Carry out a blank test with the sample.
14.3 Determination
100 — A
14.3.1 Connect the determination device according to Figure 1, heat the combustion furnace to 1230±20C (if the carrier gas is oxygen, the furnace temperature should be raised to 1380±20C), ventilate and check the analysis device to ensure that there is no leakage (use wet cotton fabric at both ends of the porcelain tube to cool the porcelain tube). 14.3.2 Add about 60mL starch absorption solution (11.6) and absorb 1mL potassium iodide solution (11.7) and place it in the absorption cup, pass the carrier gas at a flow rate of 31./min, and titrate with potassium iodate standard solution (11.8) until the color is the same as the reference solution (operated according to 14.3.2) with a light blue color, and turn off the carrier gas. 81
GB/T14949.9-94
14.3.3 Place the sample (14.1) in a porcelain boat that has been previously burned in a nitrogen flow at 1200~~1250℃ or in an oxygen flow at 1350~~1400℃ (the burning time of the empty porcelain boat with carrier gas is generally 2~3min), push it into the high temperature center of the combustion furnace, immediately plug the silicone rubber plug, pass the carrier gas at a flow rate of 31./min, and immediately drop the potassium iodate standard solution (11.8) in. To prevent the escape of sulfur dioxide, a certain amount of potassium iodate standard solution should be added in advance. Keep the liquid surface of the absorption liquid blue. When the color of the absorption liquid is the same as that of the reference liquid, continue to pass the carrier gas for 2min and it still does not change color, which is the end point.
15 Calculation of analysis results
Calculate the mass percentage of sulfur according to formula (2): S(%) = T(Vi= V.) × 100
Wherein: T--titer of potassium iodate standard solution, grams of sulfur equivalent per milliliter of solution; V, volume of potassium iodate standard solution consumed in the determination of the sample, mL; V.--volume of potassium iodate standard solution consumed in the blank test, mL; m-mass of the sample, g;
K--conversion factor of the mass percentage of sulfur in the completely dried sample. 16 Precision
(2)
The precision listed in this standard is the result of a joint test conducted by eight laboratories in 1990 on four uniformly distributed samples with the same uniform distribution within the determination range of this method, according to the analytical steps of this method, and the data were summarized and statistically analyzed in accordance with the national standard GB6379. The repeatability and reproducibility R are shown in Table 2. The original data are shown in Appendix A2 (Supplement). Table 2
Level, %(m/m）
0.011~0.29
Repeatability r
r=0. 000 722 9+0. 026 01m
Reproducibility R
IgR-.1.424+0.6560lgm
Repeatability is the maximum difference between two independent test results at a 95% probability level when two single test results are made by the same operator, in the same laboratory, using the same instrument, and within a short period of time under normal and correct operation conditions. Reproducibility is the maximum difference between two independent test results at a 95% probability level when two single test results are made by two operators, in different laboratories, on the same sample under normal and correct operation conditions. If the difference between two independent test results exceeds the corresponding repeatability and reproducibility values, the two results are considered suspicious. Number
Laboratory
GB/T 14949.9—94
Appendix A1
Original data of precision test
(Supplement)
Additional notes:
GB/T14949.9-94
Appendix A2
Original data of precision test
(Supplement)
This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. S-3
This standard was drafted by the Mineral Geology Research Institute of China Nonferrous Metals Industry Corporation and the Changsha Mining and Metallurgical Research Institute of the Ministry of Metallurgical Industry. This standard was drafted by the Guangxi Metallurgical Research Institute and Xinyu Iron and Steel General Plant. The main drafters of this standard are Liu Liangcheng, Youyou Shen, Zhou Juhan, Wan Jiebao and Cheng Yanqing. 6.121) Filling, 4, 5 two washing bottles are not needed); 6 combustion furnace (temperature can reach 1400 (); 7 temperature controller (controllable 1400); 8 glass single ball drying tube (with dry cotton wool inside); 9 sulfur absorption cup (for absorbing sulfur dioxide): 10 burette; 11: porcelain tube (inner diameter 23l.2mm, length 600mm); 12 porcelain boat (length 88mm.77mm or 96mm); 13 sulfur absorption cup (for reference) 12.2 sulfur absorption cup see Figure 2.
13 test sample
GB/T14949.9--94
022~23
float (frosted)
spray downward
the test sample should pass 0.100 mm sieve and air-dried under laboratory conditions. 14 Analysis steps
14.1 Sample quantity
Weigh 0.5-1.0g sample, accurate to 0.0001g. When the sulfur content in the sample is less than or equal to 0.02%, weigh about 1g, and when it is greater than 0.02%, weigh about 0.5g.
While measuring, weigh the sample to measure the mass fraction of wet water (A). When calculating the sulfur content, the result (mass white fraction) should be multiplied by the conversion factor K, which is the mass percentage of sulfur measured in the completely dry sample. Conversion factor K
14.2 Blank test
Perform a blank test along with the sample.
14.3 Determination
100 — A
14.3.1 Connect the measuring device according to Figure 1, heat the combustion furnace to 1230±20C (if the carrier gas is oxygen, the furnace temperature should be raised to 1380±20C), ventilate and check the analytical device to ensure that there is no leakage (use wet cotton fabric at both ends of the porcelain tube to cool the porcelain tube). 14.3.2 Add about 60mL of starch absorption liquid (11.6) and absorb 1mL of potassium iodide solution (11.7) and place it in the absorption cup. Pass the carrier gas at a flow rate of 31./min, and titrate with potassium iodate standard solution (11.8) until it is light blue with the same color as the reference solution (operated according to 14.3.2), and turn off the carrier gas. 81
GB/T14949.9-94
14.3.3 Add the test sample (1 4.1) Place in a porcelain boat that has been previously burned in a nitrogen flow at 1200~~1250℃ or in an oxygen flow at 1350~~1400℃ (the burning time of the empty porcelain boat with carrier gas is generally 2~3min), push it into the high temperature center of the combustion furnace, immediately plug the silicone rubber plug, pass the carrier gas at a flow rate of 31./min, and immediately drip in potassium iodate standard solution (11.8). To prevent the escape of sulfur dioxide, a certain amount of potassium iodate standard solution should be added in advance]. Keep the liquid surface of the absorption liquid blue. When the color of the absorption liquid is consistent with that of the reference liquid, continue to pass the carrier gas for 2min without changing color, which is the end point.
15 Calculation of analysis results
Calculate the mass percentage of sulfur according to formula (2): S(%) = T(Vi= V.) × 100
Wherein: T—titre of potassium iodate standard solution, grams of sulfur equivalent per milliliter of solution; V, volume of potassium iodate standard solution consumed in the determination of the sample, mL; V.—volume of potassium iodate standard solution consumed in the blank test, mL; m—mass of the sample, g;
K—conversion factor of the mass percentage of sulfur in the completely dried sample. 16 Precision
(2)
The precision listed in this standard is the result of a joint test conducted by eight laboratories in 1990 on four uniformly distributed samples with the same uniform distribution within the determination range of this method, according to the analytical steps of this method, and the data were summarized and statistically analyzed in accordance with the national standard GB6379. The repeatability and reproducibility R are shown in Table 2. The original data are shown in Appendix A2 (Supplement). Table 2
Level, %(m/m）
0.011~0.29
Repeatability r
r=0. 000 722 9+0. 026 01m
Reproducibility R
IgR-.1.424+0.6560lgm
Repeatability is the maximum difference between two independent test results at a 95% probability level when two single test results are made by the same operator, in the same laboratory, using the same instrument, and within a short period of time under normal and correct operation conditions. Reproducibility is the maximum difference between two independent test results at a 95% probability level when two single test results are made by two operators, in different laboratories, on the same sample under normal and correct operation conditions. If the difference between two independent test results exceeds the corresponding repeatability and reproducibility values, the two results are considered suspicious. Number
Laboratory
GB/T 14949.9—94
Appendix A1
Original data of precision test
(Supplement)
Additional notes:
GB/T14949.9-94
Appendix A2
Original data of precision test
(Supplement)
This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. S-3
This standard was drafted by the Mineral Geology Research Institute of China Nonferrous Metals Industry Corporation and the Changsha Mining and Metallurgical Research Institute of the Ministry of Metallurgical Industry. This standard was drafted by the Guangxi Metallurgical Research Institute and Xinyu Iron and Steel General Plant. The main drafters of this standard are Liu Liangcheng, Youyou Shen, Zhou Juhan, Wan Jiebao and Cheng Yanqing. 6.121) Filling, 4, 5 two washing bottles are not needed); 6 combustion furnace (temperature can reach 1400 (); 7 temperature controller (controllable 1400); 8 glass single ball drying tube (with dry cotton wool inside); 9 sulfur absorption cup (for absorbing sulfur dioxide): 10 burette; 11: porcelain tube (inner diameter 23l.2mm, length 600mm); 12 porcelain boat (length 88mm.77mm or 96mm); 13 sulfur absorption cup (for reference) 12.2 sulfur absorption cup see Figure 2.
13 test sample
GB/T14949.9--94
022~23
float (frosted)
spray downward
the test sample should pass 0.100 mm sieve and air-dried under laboratory conditions. 14 Analysis steps
14.1 Sample quantity
Weigh 0.5-1.0g sample, accurate to 0.0001g. When the sulfur content in the sample is less than or equal to 0.02%, weigh about 1g, and when it is greater than 0.02%, weigh about 0.5g.
While measuring, weigh the sample to measure the mass fraction of wet water (A). When calculating the sulfur content, the result (mass white fraction) should be multiplied by the conversion factor K, which is the mass percentage of sulfur measured in the completely dry sample. Conversion factor K
14.2 Blank test
Perform a blank test along with the sample.
14.3 Determination
100 — A
14.3.1 Connect the measuring device according to Figure 1, heat the combustion furnace to 1230±20C (if the carrier gas is oxygen, the furnace temperature should be raised to 1380±20C), ventilate and check the analytical device to ensure that there is no leakage (use wet cotton fabric at both ends of the porcelain tube to cool the porcelain tube). 14.3.2 Add about 60mL of starch absorption liquid (11.6) and absorb 1mL of potassium iodide solution (11.7) and place it in the absorption cup. Pass the carrier gas at a flow rate of 31./min, and titrate with potassium iodate standard solution (11.8) until it is light blue with the same color as the reference solution (operated according to 14.3.2), and turn off the carrier gas. 81
GB/T14949.9-94
14.3.3 Add the test sample (1 4.1) Place in a porcelain boat that has been previously burned in a nitrogen flow at 1200~~1250℃ or in an oxygen flow at 1350~~1400℃ (the burning time of the empty porcelain boat with carrier gas is generally 2~3min), push it into the high temperature center of the combustion furnace, immediately plug the silicone rubber plug, pass the carrier gas at a flow rate of 31./min, and immediately drip in potassium iodate standard solution (11.8). To prevent the escape of sulfur dioxide, a certain amount of potassium iodate standard solution should be added in advance]. Keep the liquid surface of the absorption liquid blue. When the color of the absorption liquid is consistent with that of the reference liquid, continue to pass the carrier gas for 2min without changing color, which is the end point.
15 Calculation of analysis results
Calculate the mass percentage of sulfur according to formula (2): S(%) = T(Vi= V.) × 100
Wherein: T—titre of potassium iodate standard solution, grams of sulfur equivalent per milliliter of solution; V, volume of potassium iodate standard solution consumed in the determination of the sample, mL; V.—volume of potassium iodate standard solution consumed in the blank test, mL; m—mass of the sample, g;
K—conversion factor of the mass percentage of sulfur in the completely dried sample. 16 Precision
(2)
The precision listed in this standard is the result of a joint test conducted by eight laboratories in 1990 on four uniformly distributed samples with the same uniform distribution within the determination range of this method, according to the analytical steps of this method, and the data were summarized and statistically analyzed in accordance with the national standard GB6379. The repeatability and reproducibility R are shown in Table 2. The original data are shown in Appendix A2 (Supplement). Table 2
Level, %(m/m）
0.011~0.29
Repeatability r
r=0. 000 722 9+0. 026 01m
Reproducibility R
IgR-.1.424+0.6560lgm
Repeatability is the maximum difference between two independent test results at a 95% probability level when two single test results are made by the same operator, in the same laboratory, using the same instrument, and within a short period of time under normal and correct operation conditions. Reproducibility is the maximum difference between two independent test results at a 95% probability level when two single test results are made by two operators, in different laboratories, on the same sample under normal and correct operation conditions. If the difference between two independent test results exceeds the corresponding repeatability and reproducibility values, the two results are considered suspicious. Number
Laboratory
GB/T 14949.9—94
Appendix A1
Original data of precision test
(Supplement)
Additional notes:
GB/T14949.9-94
Appendix A2
Original data of precision test
(Supplement)
This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. S-3
This standard was drafted by the Mineral Geology Research Institute of China Nonferrous Metals Industry Corporation and the Changsha Mining and Metallurgical Research Institute of the Ministry of Metallurgical Industry. This standard was drafted by the Guangxi Metallurgical Research Institute and Xinyu Iron and Steel General Plant. The main drafters of this standard are Liu Liangcheng, Youyou Shen, Zhou Juhan, Wan Jiebao and Cheng Yanqing. 6.12) × 100
Wherein: T—titre of potassium iodate standard solution, equivalent to grams of sulfur per milliliter of solution; V, volume of potassium iodate standard solution consumed in the determination of the sample, mL; V.—volume of potassium iodate standard solution consumed in the blank test, mL; m—mass of the sample, g;
K—conversion factor of the mass percentage of sulfur in the completely dried sample. 16 Precision
(2)
The precision listed in this standard is the result of a joint test conducted by eight laboratories in 1990 on four uniformly distributed samples with the same uniform distribution within the determination range of this method, according to the analytical steps of this method, and the data were summarized and statistically analyzed in accordance with the national standard GB6379. The repeatability and reproducibility R are shown in Table 2. The original data are shown in Appendix A2 (Supplement). Table 2
Level, %(m/m）
0.011~0.29
Repeatability r
r=0. 000 722 9+0. 026 01m
Reproducibility R
IgR-.1.424+0.6560lgm
Repeatability is the maximum difference between two independent test results at a 95% probability level when two single test results are made by the same operator, in the same laboratory, using the same instrument, and within a short period of time under normal and correct operation conditions. Reproducibility is the maximum difference between two independent test results at a 95% probability level when two single test results are made by two operators, in different laboratories, on the same sample under normal and correct operation conditions. If the difference between two independent test results exceeds the corresponding repeatability and reproducibility values, the two results are considered suspicious. Number
Laboratory
GB/T 14949.9—94
Appendix A1
Original data of precision test
(Supplement)
Additional notes:
GB/T14949.9-94
Appendix A2
Original data of precision test
(Supplement)
This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. S-3
This standard was drafted by the Mineral Geology Research Institute of China Nonferrous Metals Industry Corporation and the Changsha Mining and Metallurgical Research Institute of the Ministry of Metallurgical Industry. This standard was drafted by the Guangxi Metallurgical Research Institute and Xinyu Iron and Steel General Plant. The main drafters of this standard are Liu Liangcheng, Youyou Shen, Zhou Juhan, Wan Jiebao and Cheng Yanqing. 6.12) × 100
Wherein: T—titre of potassium iodate standard solution, equivalent to grams of sulfur per milliliter of solution; V, volume of potassium iodate standard solution consumed in the determination of the sample, mL; V.—volume of potassium iodate standard solution consumed in the blank test, mL; m—mass of the sample, g;
K—conversion factor of the mass percentage of sulfur in the completely dried sample. 16 Precision
(2)
The precision listed in this standard is the result of a joint test conducted by eight laboratories in 1990 on four uniformly distributed samples with the same uniform distribution within the determination range of this method, according to the analytical steps of this method, and the data were summarized and statistically analyzed in accordance with the national standard GB6379. The repeatability and reproducibility R are shown in Table 2. The original data are shown in Appendix A2 (Supplement). Table 2
Level, %(m/m）
0.011~0.29
Repeatability r
r=0. 000 722 9+0. 026 01m
Reproducibility R
IgR-.1.424+0.6560lgm
Repeatability is the maximum difference between two independent test results at a 95% probability level when two single test results are made by the same operator, in the same laboratory, using the same instrument, and within a short period of time under normal and correct operation conditions. Reproducibility is the maximum difference between two independent test results at a 95% probability level when two single test results are made by two operators, in different laboratories, on the same sample under normal and correct operation conditions. If the difference between two independent test results exceeds the corresponding repeatability and reproducibility values, the two results are considered suspicious. Number
Laboratory
GB/T 14949.9—94
Appendix A1
Original data of precision test
(Supplement)
Additional notes:
GB/T14949.9-94
Appendix A2
Original data of precision test
(Supplement)
This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. S-3
This standard was drafted by the Mineral Geology Research Institute of China Nonferrous Metals Industry Corporation and the Changsha Mining and Metallurgical Research Institute of the Ministry of Metallurgical Industry. This standard was drafted by the Guangxi Metallurgical Research Institute and Xinyu Iron and Steel General Plant. The main drafters of this standard are Liu Liangcheng, Youyou Shen, Zhou Juhan, Wan Jiebao and Cheng Yanqing. 6.12
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